Described below are a method and a device for ultrasonic testing of a test object.
Very varied ultrasonic testing methods are known for nondestructive testing of test objects. The analysis technique SAFT (Synthetic Aperture Focusing Technique) is known for better localization and separation of defects in nondestructive testing with ultrasound. Inspection is performed in this case as in known ultrasonic testing, but the data are recorded without rectification. In the subsequent analysis of the measurement data, amplitude sums are determined from a multiplicity of measurement signals for respective small volume elements, which are also denoted as so-called voxels. Ultrasonic testing can be used with the aid of SAFT analysis, for example given manual movement of a probe which emits the ultrasonic pulses and receives the corresponding echo signals. Such SAFT testing is described, for example, in DE 10 2013 200974.7.
It is possible through the use of so-called phased array probes for test objects to be scanned not just mechanically but also electronically, that is to say a plurality of measurements are carried out in a defined grid by a kind of electronic displacement of the active zone of the probe. In the case of a stationary probe, data which have been recorded with the same electronic scan can be evaluated with the SAFT analysis. This works both for an unmoved probe and in the case of a probe moved during the electronic scan when the exact transmitted and received position as well as the angle of incidence and focusing at the reconstruction instant are known.